Nobuki Miyamoto
Sapporo Medical University
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Publication
Featured researches published by Nobuki Miyamoto.
Modern Pathology | 2007
Taiga Takahashi; Katsuhiko Nosho; Hiroyuki Yamamoto; Masashi Mikami; Hiroaki Taniguchi; Nobuki Miyamoto; Yasushi Adachi; Fumio Itoh; Kohzoh Imai; Yasuhisa Shinomura
Morphologically, colorectal adenomas can be divided into two groups, protruded-type and flat-type. However, the accurate frequencies of genetic and epigenetic alterations in flat-type colorectal advanced adenomas (laterally spreading tumors) have remained largely unknown. In the current study, we investigated genetic and epigenetic alterations in 101 flat-type colorectal advanced adenomas and 68 protruded-type colorectal advanced adenomas by using direct DNA sequencing and quantitative real-time PCR (MethyLight), respectively. KRAS mutation was detected in a significantly higher percentage of flat-type adenomas (35%) than in protruded-type adenomas (13%). When the samples were limited to the tumors in the distal colon, the difference of KRAS mutation was still significant. KRAS mutation in G-to-A transitions at codons 12 and 13 was detected in a significantly higher percentage of flat-type adenomas (26%) than in protruded-type adenomas (9%). BRAF and β-catenin mutations were detected in 3 and 8% of the 101 flat-type adenomas, respectively. No significant difference was found between frequencies of those mutations in flat-type adenomas and protruded-type adenomas. Methylations of MGMT, CDKN2A (p16) and MLH1 were detected in 28, 33 and 9% of the 101 flat-type adenomas, respectively. CDKN2A methylation was detected in a significantly lower percentage of flat-type adenomas than in protruded-type adenomas (63%). Methylation of at least one gene was detected in a significantly lower percentage of flat-type adenomas (54%) than in protruded-type adenomas (78%). In conclusion, KRAS mutation was frequently detected in flat-type advanced adenomas and the mutational patterns in most of them with KRAS mutations were a transition from G-to-A. Therefore, these genetic alterations seem to play an important role in the development of flat-type advanced adenomas, especially in the distal colon. Epigenetic alterations infrequently occurred in flat-type advanced adenomas, suggesting that they have different genetic and epigenetic alterations from those of protruded-type advanced adenomas.
World Journal of Gastroenterology | 2008
Tadateru Maehata; Hiroaki Taniguchi; Hiroyuki Yamamoto; Katsuhiko Nosho; Yasushi Adachi; Nobuki Miyamoto; Chie Miyamoto; Noriyuki Akutsu; Satoshi Yamaoka; Fumio Itoh
Carcinogenesis | 2004
Hiroyuki Yamamoto; Akravit Vinitketkumnuen; Yasushi Adachi; Hiroaki Taniguchi; Tamaki Hirata; Nobuki Miyamoto; Katsuhiko Nosho; Arisa Imsumran; Masahiro Fujita; Masao Hosokawa; Yuji Hinoda; Kohzoh Imai
Carcinogenesis | 2007
Katsuhiko Nosho; Hiroyuki Yamamoto; Taiga Takahashi; Masashi Mikami; Hiroaki Taniguchi; Nobuki Miyamoto; Yasushi Adachi; Yoshiaki Arimura; Fumio Itoh; Kohzoh Imai; Yasuhisa Shinomura
Cancer Letters | 2007
Nobuki Miyamoto; Hiroyuki Yamamoto; Hiroaki Taniguchi; Chie Miyamoto; Mariko Oki; Yasushi Adachi; Kohzoh Imai; Yasuhisa Shinomura
Oncology Letters | 2011
Chie Miyamoto; Nobuki Miyamoto; Hiroyuki Yamamoto; Kohzoh Imai; Yasuhisa Shinomura
Gastroenterology | 2011
Yasushi Adachi; Yasutaka Sukawa; Hiroyuki Yamamoto; Katsuhiko Nosho; Chie Miyamoto; Nobuki Miyamoto; Hiroaki Taniguchi; Mayumi Nakazawa; Hiromu Suzuki; Shigeru Sasaki; Yoshiaki Arimura; Yasuhisa Shinomura
Gastroenterology | 2011
Shinya Ohashi; Azal Ahmadi; Sanders Chang; Kei Nakagawa; Gabrielle S. Wong; Nobuki Miyamoto; Katharine D. Grugan; Andres J. Klein-Szanto; Meenhard Herlyn; J. Alan Diehl; Hiroshi Nakagawa
Gastroenterology | 2011
Yasutaka Sukawa; Hiroyuki Yamamoto; Katsuhiko Nosho; Chie Miyamoto; Nobuki Miyamoto; Hiroaki Taniguchi; Yasushi Adachi; Mayumi Nakazawa; Hiromu Suzuki; Shigeru Sasaki; Yoshiaki Arimura; Yasuhisa Shinomura
Gastroenterology | 2011
Chie Miyamoto; Yasutaka Sukawa; Nobuki Miyamoto; Hiroyuki Yamamoto; Katsuhiko Nosho; Yasushi Adachi; Hiroaki Taniguchi; Mayumi Nakazawa; Hiromu Suzuki; Shigeru Sasaki; Yoshiaki Arimura; Yasuhisa Shinomura
